18results about "Polyphase network asymmetry reduction" patented technology

The application discloses an automatic short-circuit device and a CT current loop, the device is arranged correspondingly with each-phase current transformer CT conducting plate, the conducting plate comprises a first conducting plate and a second conducting plate; the automatic short-circuit device comprises an overvoltage control module, a short-circuit control module and a short-circuit execution module; the overvoltage control module is used for controlling the short-circuit control module to work when the voltage between the first conducting plate and the second conducting plate is overvoltage; the short-circuit execution module is connected with the second conducting plate, the short-circuit control module is connected with the overvoltage control module, the short-circuit control module is used for driving the short-circuit execution module to execute a short-circuit operation according to the control of the overvoltage control module, so as to short-circuit each second conducting plate of adjacent phases; the first conducting plate and the second conducting plate are connected through current terminals. The automatic short-circuit device can realize the short-circuit of the current transformer CT conducting plate when the current transformer CT conducting plate is open.

The application discloses a three-phase unbalanced power distribution network fast partitioning method based on electrical coupling strength, comprising: data preprocessing of obtained power distribution network related data, construction of power distribution network electrical data set; definition of electrical distance adjustment parameter, calculation of three-phase comprehensive electrical distance between nodes; conversion of three-phase comprehensive electrical distance between nodes into connection weight between nodes, construction of weighted undirected graph model reflecting electrical coupling strength; generation of initial partition by using modularity optimized greedy community discovery algorithm, output of high cohesion initial partition set; construction of merging evaluation function fusing both; iterative execution of area merging, output of final partition result. The application quantifies real electrical correlation between nodes accurately, realizes collaborative optimization of electrical cohesion and balance of sub-region scale, guarantees high efficiency and stability of partition calculation, and provides reliable partition support for power distribution network parallel computing, distributed control and fault self-healing scenes.

The application provides a commutation soft switching system for treating current imbalance of a power distribution network and an evaluation method. The commutation soft switching system combines a low-voltage commutation device and an intelligent soft switching device, realizes current flow transfer between different phases, flexibly adjusts the current flow transfer and current distribution between phases, is beneficial to balancing the current difference between three phases of the power distribution network, thereby improving the output efficiency of the power distribution transformer and reducing network loss. The application builds an optimization model based on network flow constraints, solves the optimization model with the minimum current imbalance degree as the target, obtains outgoing currents of each phase and outgoing average currents of three phases, and obtains an index for evaluating the commutation soft switching system for treating the current imbalance problem in the power distribution network through the size of the outgoing currents of each phase and the outgoing average currents of three phases.

The application discloses a ring main unit current transformer secondary circuit disconnection detection method and system, and relates to the field of power distribution network system protection automation. The method comprises the following steps: obtaining a power balance imbalance starting threshold value according to a power sum, judging whether a bus is power imbalanced according to the power balance imbalance starting threshold value, obtaining three-phase currents of incoming lines and outgoing lines of the bus when the bus is power imbalanced, calculating current imbalance degrees of the incoming lines and the outgoing lines of the bus according to the three-phase currents, judging whether a current transformer secondary circuit is abnormal according to the current imbalance degrees, calculating phase sudden change currents according to the obtained three-phase currents of the incoming lines and the outgoing lines of the bus at the same moment when the current transformer secondary circuit is abnormal, judging whether the phase sudden change currents satisfy a third preset condition, and if yes, the current transformer secondary circuit is disconnected. According to the power node power conservation principle, the line current transformer secondary circuit disconnection discrimination accuracy and rapidity are improved under the condition that bus voltages are normal.

The three-phase four-wire converter reverse flow prevention control device and method provided by the embodiment of the application comprises a data acquisition module, a pre-judgment decision module and a phase-by-phase reverse flow prevention control module, the phase-by-phase reverse flow prevention control module is used for determining a phase load power prediction value in a preset time period based on historical load data, real-time load data and scene feature data, determining a three-phase load imbalance coefficient based on the real-time load data, dynamically generating a phase-by-phase power adjustment instruction based on the phase load power prediction value and the three-phase load imbalance coefficient, and controlling a phase-by-phase power output value of the three-phase four-wire converter based on the phase-by-phase power adjustment instruction, so that the three-phase four-wire converter actively adjusts the output power before a load mutation, rather than passively responding to a reverse flow time; and the three-phase load imbalance coefficient is combined to realize differential adjustment of the output power, and the accuracy and adaptability of the phase-by-phase power adjustment are improved.

The application relates to a three-phase four-bridge-arm control system and method with direct-current side isolation, which comprises a first circuit breaker, a second circuit breaker, a first variable-current side module, a second variable-current side module, a voltage output module and a control module. The control module is used for collecting grid voltage, current and on-off signals, generating control instructions after processing and coordinating the operation of each module, and monitoring the system state in real time to ensure the continuity of voltage frequency and phase during the grid-connected and off-grid switching process. The three-phase four-bridge-arm control system can significantly improve the overall efficiency of the system, greatly reduce the equipment volume and cost, and effectively reduce the harmonic and electromagnetic interference. The added direct-current side isolation link provides reliable and complete electrical isolation capability, significantly enhancing the safety. The influence of the direct electrical connection of the system neutral line on the load side voltage is solved. When an asymmetric fault occurs, the fault current can be completely disconnected, improving the protection and reliability of the system.

This invention discloses a control method and related apparatus for a hybrid distribution transformer, relating to the field of flexible power distribution equipment and its control technology. The control method is applied to a hybrid distribution transformer system including a balancing bridge arm. The control method includes: real-time acquisition of electrical quantity signals from the hybrid distribution transformer system; generating a first PWM drive signal based on the electrical quantity signals to control the operation of the switching transistors in the parallel converter, thereby driving the parallel converter to inject compensation current into the line; generating a second PWM drive signal based on the electrical quantity signals to control the operation of the switching transistors in the series converter, thereby driving the series converter to inject compensation voltage into the line through the series transformer; and generating a third PWM drive signal based on the electrical quantity signals to control the operation of the switching transistors in the balancing bridge arm, thereby driving the balancing bridge arm to adjust the neutral point current. This invention solves the problems of existing technologies requiring large-capacity capacitors, incurring additional losses and electromagnetic compatibility issues, and exhibiting three-phase imbalance.

This invention discloses an intelligent terminal for phase-switching switches based on three-phase self-balancing and low-voltage fault location and isolation, belonging to the field of intelligent control technology for phase-switching switches. Through research on residual current change curves and characteristic components, distribution characteristics, and three-phase self-balancing techniques before and after a low-voltage distribution area fault, this invention proposes a residual current protection strategy using the transient component of the residual current as the logic action condition to achieve fault location and isolation in low-voltage distribution areas of the distribution network. It automatically acquires line impedance to deduce three-phase imbalance in the distribution area and combines it with phase-to-phase voltage difference to achieve three-phase self-balancing. Furthermore, through research on low-power wireless technology, it enables the uploading of measurement and fault information, providing data support for the analysis and processing of low-voltage faults and improving the automation level of the distribution network.

The application discloses a kind of based on dynamic compensation's power distribution line's balance control method and system, the present application relates to the technical field of power distribution line, based on the identification of this dynamic compensation event to determine multiple dynamic compensation projects, according to the project content of multiple dynamic compensation projects, corresponding project priority and the multiple real-time data of main line determine corresponding alternating compensation current, improve the accuracy of alternating dynamic compensation current.According to the harmonic processing of this alternating compensation current to determine corresponding current control event, and mark corresponding zero sequence current, to change the current state of the main line;Real-time load of the main line is collected, according to the real-time load of the main line and corresponding current state determines the balance event of power distribution line, based on the balance event, the three-phase load current and three-phase grid voltage of the main line determines dynamic balance system, realizes the control of the current state of the main line, improves the accuracy of dynamic balance system.

The application provides a three-phase unbalanced load adjustment method and system, and belongs to the technical field of power distribution network of power systems. The method acquires load information of each electric meter and calculates the three-phase unbalance degree of the total meter by collecting the power consumption data and phase information of the total meter and all single-phase electric meters in the power distribution area in real time. When the three-phase unbalance degree of the total meter exceeds the set threshold, a load prediction model is established based on the historical power consumption data. A digital power grid model containing line resistance parameters, line reactance parameters and load power parameters is constructed, and various phase modulation schemes are simulated in the model. The weighted scoring method is used to comprehensively evaluate the three-phase unbalance degree improvement effect, construction distance factors and operation time factors. According to the evaluation results, a phase modulation work order containing the list of single-phase electric meters that need to be modulated and the target phase is generated and sent to the field terminal through a communication network to guide the phase modulation operation. The application can accurately guide the phase modulation operation, reduce the number of repeated adjustments, and significantly improve the three-phase unbalance treatment efficiency.

The application relates to a magnetic holding relay driving control system applied to a commutating switch, which comprises a control device, a driving power switch device, a switching driving device and a series three-phase double-coil magnetic holding relay; the control device is electrically connected with the driving power switch device and the switching driving device respectively, the driving power switch device is electrically connected with the switching driving device, and the switching driving device is electrically connected with the series three-phase double-coil magnetic holding relay. The application realizes the function of the commutating switch based on the series three-phase double-coil magnetic holding relay, has high reliability, can effectively eliminate the phase-to-phase short circuit problem caused by abnormal driving signals, simultaneously reduces the load power-off phenomenon caused by the open circuit of the relay, and meets the technical requirement of the commutating switch.

The invention relates to a method for determining an unsymmetrical oscillation during operation of an electrical device (1), which is connected to a high-voltage network, wherein vibrations of the electrical device (1) are detected by means of an oscillation sensor (8), which provides measurement values on the output side, the measurement values and / or values derived from the measurement values are transmitted from the oscillation sensor (8) via a short-range communication connection (11) to a communication unit (12), the measurement values and / or values derived from the measurement values are transmitted from the communication unit (12) via a long-range communication connection (13) to a data processing cloud (9), the data processing cloud (9) decomposes the measurement values and / or values derived from the measurement values into their frequency components by means of a Fourier transformation in order to obtain a frequency spectrum, the even and odd frequency components of the frequency spectrum are determined in dependence on the fundamental frequency of the high-voltage power supply network, and a ratio R with respect to one another is determined, and when the ratio R exceeds a predetermined threshold value, it is derived that an unsymmetrical oscillation is present.

The application discloses a phase sequence automatic identification and correction distribution box system, comprising: a three-phase voltage synchronous sampling module; a Clarke transformation calculation unit; a sequential probability ratio test decision unit; a cross-validation unit, which is used for reconstructing a space vector rotation angle from the two-phase stationary coordinate system components, converting it into an equivalent phase-to-phase included angle, and then substituting it into a cost function to perform independent scoring, and performing consistency comparison with the result of the sequential probability ratio test decision unit; a safety interlocking unit; a correction execution unit; the three-phase imbalance factor output by the Clarke transformation calculation unit is fed back to the sequential probability ratio test decision unit in real time, and the noise model parameters thereof are dynamically adjusted, so that a signal quality adaptive closed-loop decision mechanism is formed. In summary, the application provides an intelligent phase sequence automatic identification and correction distribution box system which can break through the contradiction between detection speed and decision reliability, has signal quality adaptive capability, and provides a quantifiable misjudgment rate guarantee.

The application provides an automatic through-phase device function test system and a test method, which comprise a first transformer, a second transformer and a simulation load, a three-phase primary winding of the first transformer is used for being connected with an external power supply, a secondary winding of the first transformer comprises a first connection terminal and a second connection terminal, the first connection terminal is connected with a primary winding of the second transformer through a first switch, the second connection terminal is connected with the primary winding of the second transformer through a second switch, and a secondary winding of the second transformer is connected with the simulation load; wherein when a power electronic switch group function test of an automatic through-phase device is carried out, the power electronic switch group of the automatic through-phase device is connected between the first connection terminal, the second connection terminal and the primary winding of the second transformer. Through the application, the power electronic switch group of the automatic through-phase device can be connected, so that the core function and operation effect of the automatic through-phase device can be tested.

The application relates to a voltage regulation method and device, computer equipment, a storage medium and a program product. The method comprises the following steps: acquiring electrical data of a power distribution network under at least one phase; the power distribution network, a target load and a voltage regulation device are connected in series; the voltage regulation device is used for regulating the voltage of the target load; the power distribution network comprises a three-phase alternating current source and an impedance load; the three-phase alternating current source is connected in series with the impedance load; for each phase, according to the electrical data under the phase, the voltage regulation parameter under the phase is determined; according to the voltage regulation parameter, the pulse width modulation signal under the phase is determined; according to the pulse width modulation signals under the phases, the voltage regulation device is controlled to regulate the voltage of the target load; in the above process, for each phase, based on the voltage regulation parameter, the pulse width modulation signal under the phase can be determined, so that independent regulation and control of three phases can be realized, and more accurate regulation and control can be realized for the problem of three-phase imbalance.